This section stipulates the formula by which nine states and some jurisdictions in others are brought under Section 5, which requires them to get federal permission — “preclearance” — for even the most minor changes in voting procedures. The 15th Amendment empowers Congress to enforce with “appropriate legislation” the right to vote. Sections 4 and 5 were appropriate 48 years ago, when the preclearance provisions were enacted for five years. They have been extended four times, most recently in 2006 for 25 years.

The Voting Rights Act (VRA) is the noblest legislation in United States history, more transformative than the 1862 Homestead Act, the 1862 Morrill Act (land-grant colleges) or the 1944 GI Bill of Rights. But extraordinary laws that once were constitutional, in spite of being discordant with the nation’s constitutional architecture, can become unconstitutional when facts that made the law appropriate change. The most recent data, such as registration and voting rates, on which Section 4 is based, are from 1972. The data would have been 59 years old when the most recent extension expired in 2031. Tuesday’s decision prevents this absurdity that Congress embraced.

In 2009, the court chose not to rule on the continuing constitutionality of the VRA’s formula. The court — Chief Justice Roberts writing for the majority — clearly challenged Congress to update the VRA because it “imposes current burdens and must be justified by current needs.” On Tuesday, Roberts tersely said Section 4 is “based on decades-old data and eradicated practices.”

The 2006 extension was passed by votes of 390-33 and 98-0 in the House and Senate, respectively. Justice Antonin Scalia suggested during February’s oral argument that these numbers indicated not conviction based on reflection about continuing necessities but rather the reluctance of risk-averse legislators to vote against something with the “wonderful” name Voting Rights Act. Scalia should have cited the actual name of the 2006 extension: the “Fannie Lou Hamer, Rosa Parks, and Coretta Scott King Voting Rights Act Reauthorization and Amendments Act.” It is anti-constitutional to argue that it would have been admirable “restraint” for the court to respect Congress’s decision to extend all of the VRA — whether from conviction, cowardice or sloth — regardless of what the court has called the act’s “substantial federalism costs.”

The Supreme Court’s 1896 Plessy v. Ferguson decision affirming the constitutionality of racial segregation in separate but supposedly equal public accommodations rejected the idea that such segregation imposed a “badge of inferiority.” But of course it did, as the court acknowledged in its 1954 school desegregation ruling. And during oral argument in February, Justice Stephen Breyer suggested the VRA remains constitutional because it acknowledges the South’s continuing moral inferiority. He likened Southern racism to a dormant but still dangerous disease:

“Imagine a State has a plant disease, and in 1965 you can recognize the presence of that disease. . . . Now, it’s evolved. . . . But we know one thing: The disease is still there in the state.”

Breyer’s insinuation was that we “know” the covered jurisdictions remain uniquely diseased, or potentially so. Tuesday, Roberts’s response was that (in words from a prior court ruling) “the constitutional equality of the States is essential to the harmonious operation of the scheme upon which the Republic was organized.”

Section 5 is now a nullity because it lacks force absent a Section 4 formula for identifying covered jurisdictions, and today’s Congress will properly refuse to enact another stigmatizing formula. On Tuesday, however, the court paid the VRA the highest possible tribute by saying the act’s key provision is no longer constitutional because the act has changed pertinent facts that once made it so.